Method of applying protective coatings to shoes and other objects



Dec. 21, 192.7. MI LER 2,102,804

I METHOD OF APPLYING PROTECTIVE COATINGS TO SHOES AND OTHER OBJECTS Filed Jan. 21, 1935 INVENTOR m-IAIQLEJMILL Patented Dec. 21, 1937 UNITED STATES METHOD OF APPLYING PROTECTIVE COAT- INGS TO SHOES AND OTHER OBJECTS Charles Miller, Long Island City, N. Y.; Gordon Miller executrix of said Charles Miller, dc-,

ceased Application January 21, 1935, Serial No. 2,633

Claims. ((112-142) The present invention relates to the manufacture of shoes, and more particularly, to the treatment of shoe uppers in connection with the application thereto of protective coatings to pro- 5 tect them against soiling and damage during the various shoe manufacturing operations.

It has been proposed to coat shoe uppers with a thin film of latex or a latex composition by spraying the latex or the latex composition on the shoe upper to prevent the upper from being soiled. It is desirable, however, to omit the coating from certain portions of the upper, such as the heel and toe portions, until after the upper is lasted and smoothing operations on the toe and heel portions thereof are performed. This constitutes one object of the present invention.

In utilizing latex coated uppers in the manufacture of shoes in which the marginal portion of the upper is adhesively united with the out- 20 sole, it is important to roughen the said portion of the upper before applying the adhesive in order to obtain a good adhesive bond between said portion and the outsole. It is very diflicult, if not impossible, however, to roughen said marginal portions of the upper without tearing or otherwise removing the latex coating from adjacent portions of the upper which are the very portions which, at least in the manufacture of cemented shoes, are most needful of protection against soiling, because the adhesive is applied adjacent these portions and unless careful precautions are taken the adhesive spreads over these portions and stains or otherwise soils them. Another object of this invention is to provide 5 a method of roughening the marginal portions of shoe uppers coated with latex so as to preserve said coating in the region of the roughened portions.

Another object of the invention is to prevent I 45 the various tools and machine parts utilized in manufacturing shoes due to the relatively high frictional resistance oiTered by the latex to the action of the tools or the machine parts. This difiiculty manifests itself particularly in the operations involving the use of the pull over, bed lasting, nigger head, seat trimmer, and edge trimmer machines. It is another object of this invention to eliminate this difiiculty.

Ayet further object of this invention is generally to improve the art of applying protective coatings or coverings to shoe uppers and other objects.

The above objects of the invention and other objects ancillary thereto will best be understood the bleeding or running of colors in multi-color from the following description, considered in connection with the accompanying drawing.

In the drawing:

Fig. 1 is a plan view of an upper illustrating one step in the present method;

Fig. 2 is a perspective view of a form for sup.- porting the upper;

Fig. 3 is a perspective view of a shoe upper on a last illustrating the invention as applied to the method of making cemented shoes.

For convenience in reference the terms latex and latex coating will be employed to designate the protective liquid material and the protective coating formed from said material when the latter is applied to the shoe uppers, but said material may consist of any latex or similar composition utilized as protective coatings for shoes or other articles or materials. Referring to Fig. 1, there is shown for the purposes of illustration only, a shoe upper ill having side portions I2, a toe portion M, and heel portions Hi. When the shoe is lasted, wrinkles usually form at the heel and toe portions, while the side portions are substantially free from wrinkles. Accordingly, it is the usual practice in the manufacture of shoes to perform certain well known smoothing operations on said heel and toe portionsJ As the latex coating tends to interfere with these operations,

suitable instrument may be used for this purpose as, for example, a shoe-makers awl having a blunt point so as not to cut or scar the material of the upper. In lieu of the awl, or similar tool for scoring the latex coating, there may be utilized convex plates of the contour of the toe and heel portions, said plates having downturned peripheral flanges the edges of which by engagement with the latex coating are adapted to score the latter. After the coating is marked or scored, it is allowed to dry, and after it has dried the portions outlined by said lines of scoring can be readily peeled OE and thus rapidly refrom the latex coating. This method of selectively coating shoe uppers with latex has been found very satisfactory in practice and is the preferred method, but it is within the scope of the present invention to otherwise provide spraycoated uppers with uncoated portions and, ac-

cording to another method, the portions which are desired to be uncoated may be masked or covered in any suitable way to prevent the latex spray from reaching said portions. After the smoothing operations are performed on the uncoated portions of the upper, the latter may be re-coated to protect them during the subsequent stages of the manufacture of the shoe.

When the upper comprises materials of contrasting colors, the color of one material may bleed or run into the color of the other material when the liquid latex is applied. Also, as shoe uppers are made ,of porous materials, the liquid latex may penetrate into the material to an extent which will interfere with or prevent the solidified coating from being peeled off or otherwise readily removed. These difiiculties are eliminated according to the present invention by applying to the material a coating of acidic powder before the latex is applied. The acidic powder constitutes a coagulating agent and its action is to rapidly coagulate the latex when the latter is applied to the material thereby substantially limiting or preventing the penetration of the latex below the surface of the material. Also the coating of'powder constitutes a physical barrier to the penetration of the latex and prevents the liquid constituents thereof from effectively reaching the material so as to cause the colors to run or bleed. The acidic powder which is preferred is composed of French chalk and boric acid in the proportion of three parts by weight of French chalk to one part of boric acid. As boric acid absorbs moisture when cold, it is heated to drive off moisture and is kept at a temperature which will preclude it from absorbing moisture and becoming lumpy. Although, French chalk is preferred, starch may be utilized instead and tartaric acid or any other acidic powder may be used instead of boric acid. In some cases, the powder may be used without the acid constituent as the coating thereof on the material is frequently sufficient to prevent the colors from running or bleeding or to limit or prevent the penetration of the latex below the surface of the material. The

powder is applied to the material preferably by a spray gun although it may be applied in any other suitable way. After the latex has been applied and has solidified, it is dusted with French chalk or starch to reduce or eliminate its tacky characteristic.

It is desirable to provide difierent portions of the upper with latex coatings which differ in thickness. For example an upper for a pump provided with a binding at the edge of the foot opening should be coatedso that the latex coating on the binding is thicker than the rest of the coating because it is more difficult to remove the latex from the binding than from the rest of the upper. This is accomplished by applying the liquid latex in the usual way over the upper and the binding. and then inverting the shoe on the upper while the latex is fluid so that some of the latex from the upper flows onto the binding. The increased thickness of the latex on the binding facilitates its subsequent removal.

'In spray-coating the upper as described above, it has been found convenient to utilize the support ll shown in Fig. 2. As here shown said support comprises a wooden block having a top flat surface i3 continuous with a forwardly projecting inclined plane l5 which permits the support to be used for shoe uppers of various sizes and the forward end of which constitutes a handle l1. Side plates l9 projecting from opposite sides of the block serve to support the side portions of the upper.

After the selectively coated upper is prepared, as described above, it is assembled with a full insole or rand insole on a last and in so doing the usual instrumentalities well known in the art of shoe manufacturing, are employed depending upon the particular shoe making methods employed. In utilizing these instrumentalities, it frequently happens that the latex coating is torn or ruptured, thus exposing portions of the upper which requires protection. For example, in the method of making cemented shoes in which the marginal portion of the upper is adhesively united with the outsole, in which a nigger head machine is employed for purposes well known to those skilled in the art, one or more parts slidably engage portions of the upper and tear the latex coating at said portions principally because the frictional engagement between the machine parts and the latex coated portions engaged thereby is too great, for the reason that the latex surface has a high coefficient of friction. Similarly in using other machines, where parts thereof rub against the latex cover, the latter tears and holes are formed thereby reducing considerably the degree of protection which it is intended to provide.

This difficulty is eliminated, according to the present invention, by applying to the parts of the machine which engage the latex cover a substance which allows said parts to more easily slide over the cover. Instead of applying said substance to said machine parts or other instrumentalities, it may be applied to the portions of the latex cover engaged by said instrumentalities. In either case, a film of the friction reducing material is interposed between said latex cover and the instrumentalities which contact with or rub against the latter. A substance which has been found highly satisfactory for'this purpose is ordinary soap in liquid form and is known as Murphy's Oil Soap, a well known commercial product which may be purchased from Phoenix Oil Co.- of Cleveland, Ohio, but any other lubricant which, being inert in relation to latex, will not dissolve the latex or render it tacky may be used although "Murphys Oil Soap is pre- ,thereof is applied to a last 25.- The latex coated upper I0 is then lasted, the marginal edge portions ll of the upper being adhesively united with andin overlying relation to said insole. Before adhesivelyuniting the outsole (not shown) with the-upper, it is necessary to roughen the inner marginal edges 28 of the upper in order to obtain a good adhesive bond between the outsole and the upper. To prevent tearing of the latex coating from the outer marginal portions 80, when the portions 28 are roughened, specialtreatment is necessary. One method of treatment is to cut or score the latex coating along a line 32 which divides said portions 28 and 30. This is accomplished preferably by a hot dull knife. Then the latex coating between the inner edge of the marginal portions 34 and said line 32 can be readily removed. The latex coating having been removed, the portions 28 can be roughened in the usual way, care being taken not to disturb the adjacent latex coated portion 3%. Another method of removing the latex coating from the portions 28 is to subject the latter to the action of a fine high-speed emery wheel. A further method of removing the latex coating from the inner marginal portions 28 is to subject the latter to the action of a small disc, say one inch in diameter of lndskin rotated at high speed by means of a flexible shaft. Another method of removing the latex coating from the upper is to hold the portion to be uncoated gently against a rapidly revolving felt wheel whereby the latex coating is subjected to a slight frictional action. This frictional action removes the coating without burning, cutting, or marring the leather. A felt wheel suitable for this purpose is about two inches in diameter and one-half inch wide and may be driven at high speed by attachment to the shaft of a high speed edge trimming machine. All of these methods have been found satisfactory but the removal of the latex coating by cutting the same with a hot dull knife is preferred.

After the shoe is completed, the latex coating may be removed readily, usually by peeling it from the material. It is sometimes dimcult, however, to remove the latex from certain portions to which access is. difficult, as for example, at the seams and at the crease in the shoe between the upper and the outsole. In such cases, the latex may be removed or rendered invisible by applying thereto a hot tool, such as a heated putty knife, having a dull edge so as not'to mar the material of the shoe. In order to render the latex substantially invisible in case of failure to remove portions thereof, the liquid latex is preferably colored to correspond as nearly as possible to the color of the material to which it is applied.

In coating shoes or other objects according to one form of the present invention there is first sprayed onto the object a light or-very thin coat ing of latex which forms a very thin film which, although sufiiciently thick to cover the object is too thin to be readily peeled off the object. After this thin film has been applied, a second coating is applied to form, in conjunction with said first coating, afilm or complete coating which is sumciently thick to be readily peeled ofl and which is more effective as a protective covering than the first coating. It has been found that said first coating does not penetrate below the surface of the object to an extent sumcient to interfere with the removal of the complete coating from the object, and for this reason the use of a coagulant to prevent penetration of the latex as hereinbefore described may be eliminated if desired and the latex applied to the object without the intervening coating of coagulating material. It is within the scope of this invention, however, to apply a coating of coagulating material before applying said light coating of latex. In applying the several coats of latex it is preferable to permit the first coating to dry somewhat before applying the second coating.

Unless otherwise specified in the claims, certain steps in the method may be performed without others and the steps in the method may be performed in an order which differs from the. order in which they are recited in the claims. Further, while the invention has been described specifically in its application to shoe uppers, the invention, at least in certain respects, may be utilized in connection with the coating of other objects, the manufacure of which involve somewhat similar probiems as, for example, the manufacture of ladies handbags. Also as the present method is capable of many variations which will suggest themselves, in view of the present disclosure, to those skilled in the art, I do not wish to be limited to the specific steps hereindisclosed except as may be required by the appended claims and the prior art.

Having thus described the invention, what I claim is:

l. The method of making shoes which comprises providing a shoe upper, applying a latex coating thereto, then removing the coating from one or more portions of the upper to permit direct access thereto in making the shoe, subjecting said last mentioned portion or portions, in the making of the ,shoe, to the action of a tool in direct contact therewith, and subsequently removing the remainder of said coating.

2. The method of making shoes which comprises providing a shoe upper, applying a latex. coating thereto, assembling said upper with an insole on a last with the marginal edge portion of the upper overlying said insole, then removing the "latex coating from an inner edge portion only of said marginal edge portion, subjecting said inner edge portion, in the making of the shoe, to the action of a tool in direct engagernent therewith, and subsequently removing the remainder of said coating.

3. The method of making shoes which comprises assembling a latex coated upper with an insole on a last with the marginal edge portion of the upper overlying the insole and then removing the latex coating from the inner edge portion of said marginal edge portion, then roughening said inner edge portion to condition the latter for adhesive union with an outsole, then securing the outsole, and subsequently re-- moving the remainder of said coating.

4. The method of making shoes which comprises assembling a latex coatedupper with an insole on a last with the marginal edge portion of the upper overlying the insole, scoring the latex coating along a line spaced from the inner edge of said marginal edge portion, removing the latex coating from the marginal edge portion between said edge and line of scoring, then roughening the uncoated marginal edge portion, then adhesively securing an outsole to said uncoated marginal edge portion, and subsequently removing the latex coating from the rest of the upper.

5. ,Ihe method of applying a protective coating to an object having a portion which it is desired to coat and a portion which it is desired be uncoated, said method comprising the steps of spraying a liquid latex coating over all of said portions, scoring said liquid coating around the area of the portion to be uncoated while said coating is wet, permitting said coating to solidify, and then removing the portion of the solid coating defined by the lines of scoring around said area.

CHARLES MILLER. 

